Dice the onion and bell pepper. Heat the oil in a saucepan and sweat the vegetables in it. Pour in the vegetable stock and simmer over medium temperature until the vegetables are soft. Add the beans. When the beans are warm, puree the soup and season with pepper and paprika. Also tastes good with chilli flakes.
The amount is enough as a starter for 2 people or with fresh bread from the main course for 1 person.